1. Field of the Invention
The present invention is related to test heads of test handlers for integrated circuit devices. In particular, the present invention is related to a temperature control system in test heads in test handlers.
2. Description of the Related Art
The new generation of central processing units (CPU) is moving towards larger packages and multi-chip modules such as Organic Land Grid Area. High power consumption, together with the larger size, result in high temperatures within the chip body during operation. In a personal computer system, the CPU is commonly cooled by a fan or a thermoelectric cooling module which is permanently attached to the CPU by a thin film of adhesive such as epoxy. In the area of IC testing, however, the conventional method for cooling a DUT in a test handler is to use a heat sink in conjunction with a fan or compressed air blower at ambient temperatures. In other cases, there are no cooling means provided for cooling the DUT. Ambient temperature refers to the set temperature within the test handler as determined by test requirements.
A typical test head of a test handler comprises the nest and a pneumatic system for pick and place. During the testing process, the DUT is often required to operate at high ambient temperatures, while the body temperature of the DUT must not be overheated. Due to the problems of size and high power consumption as state above, the body temperature of the DUT rises rapidly during testing, resulting in high failure rates for CPU with large energy consumption when the conventional cooling methods are used.